Hi Anna,
When I used honeysuckle in arrangements in the past it looked good for about 3 days, then started to look tired. This was accelerated in a hot room. I think the honeysuckle shoots without flowers looked better in the long term, because flowers will fade quickly and make the whole arrangement look past it's best.
sweet Williams and Karma dahlias have lasted v well in a hot room, so will cuts from plants that do well in the heat, such as lavender, eryngiums, alliums, not zinnias! Dianthus Green Trick will give you a good 2 weeks.
Hope this helps,
Catrinel